Which crank length is right for me

In fact, the correct crank length can improve both the biomechanical performance of the pedal stroke and reduce the risk of injury. The most common lengths are , The goal when choosing crank length is to find the best possible balance and various factors must be taken into account when evaluating.

In the past, anthropometric values were the only useful reference in choosing the crank length. Recently, thanks to the availability of power meters and laboratory studies, it has been possible to carry out more in-depth assessments for making a proper choice. I think most riders are well served with the commonly available range of crank lengths of mm to mm, though every year we supply custom bikes with shorter than standard cranks and occasionally longer than standard cranks.

Humans are more complex than that. This is the only way to determine what works best for the individual. I suspect that other than very long or short legged riders, we all have two effective crank lengths — the one we are used to and the one we should be using.

Sometimes, happily, they are the same thing. If you get the chance to play with significant differences in crank length, do so, as it is an interesting exercise. Unless you are potentially prepared to go down the custom frame route there will be limits to what is practical.

So where do you go if you are interested in experimenting with crank length? Find more like this: Bike Fit , Miscellaneous. Note: Often, more specific answers to your questions can be found in the Comments below or in the eBooks section and FAQ page. To learn more about bike fit products offered by Steve, click here. Do you have a bike fit success story?

Please go here to share. Thinking about crank length, comes into my mind: -Lance Armstrong 1. So, quite long ones and he was a high cadence rider. I think quite the same, a shorter crank feels more smooth.

One reason could be that the shorter the crank, the shorter the horizontal diameter of the cercle, so less body weight distribution front-back little movements along the pushing stroke. Everything more stable under you. But, i think it is very hard to achieve this technique. I think you could have the same power, one riding at 80rpm and another at rpm. What to choose? Maybe different flexibility, different muscles tipe, different aerobic capacity will dictate… Anyway, lately looks like all the best pro riders choose high cadence: Lance A, Contador, Cancellara, etc.

That is some riders will perform better and feel better with proportionally long cranks and others with proportionally short cranks. Re your example of 80 rpm versus rpm. To produce the same power at different rpms, the lower cadence rider has to produce more torque per pedal stroke and a higher peak torque. This in turn means a higher peak muscular contraction which leads to greater production of fatigue metabolites.

There may be individual exceptions, or people who have trained themselves so diligently that they can cope on one day at low rpms and high intensity, but I would be surprised if they could back up for several days in a row. Sorry, i forgot to say in my example above that the one with 80rpm will use a longer crank, and the one with rpm a shorter one, thus both having the same power and torque.

Now, is it different or the same? Some years ago one of my customers was a highly ranked triathlete who competed on the circuit in the U. One year he came back from the U. I rode it up a steep hill near our old business and climbing was incredibly easy other than my knees kept trying to knock my shoulders out of joint.

I was unimpressed and wished him well. He raced it a couple of times and then tried to sell it because he was slower, much slower, not faster and his back was being hammered by the range of motion he needed to use at the hip and the massive gear he was trying to push at a ridiculously low cadence because that was all that was possible on that bike.

Let me make the assumption that neither crank length is a problem for the rider to turn efficiently; that is neither is so long as to cause a problem.

So a 5mm shorter crank would require a higher muscular effort per pedal stroke to achieve the same output at the same cadence and gear at low cadence because the lever crank arm is shorter. At high cadence it is a different story. It is easier to rev higher smoothly with a shorter crank than a longer crank and really high power outputs occur at high revs. Which is why track riders often ride shorter cranks than they would if they were road riders.

At high cadences, particularly if they have to be sustained, a shorter lever is better. Some where in there is a compromise and it is up to each rider to arrive at a good compromise.

With a more open hip angle, they sometimes find that they can keep the original handlebar position and comfortably produce power in what is now a more aerodynamic position. Setting proper seat height is the absolute first step in any fit, says Daab.

Sliding the cleats back on the shoe has the same effect as putting on a longer crankarm; a more mid-foot cleat position essentially adds to your leg extension at the bottom of the pedal stroke. That said, some riders benefit from a mid-foot cleat position for other reasons, like reducing forefoot pain or tingling. Need shorter or longer cranks? Here are the broadest stock options from each major component maker.

Road cranksets are typically available in a wider size range than mountain bike cranksets. Most retailers do not stock cranksets outside of the standard mmmm range, but will be able to special order other sizes. Need more? Zinn Cycles makes a range of cranksets for road and mountain bikes that start at mm and go all the way up to mm long.

Bikes and Gear. Deciding on the crank length is not a simple matter, though. The handlebar and saddle position can influence how well the legs are moving, as can the cleat position. And because he is not working on modifying an existing bike, he is free to customise the geometry of the frame to accommodate each part of the bike, including the cranks.

Putting a long crank mm on a bike with a low bottom bracket will cause problems with pedal strike when cornering. Interestingly, Moody also sees crank length as having an effect on the way that a rider can balance their weight on the bike. Both Morton and Moody are generally happy with the range of crank lengths available and consider 2. Nevertheless, there may be a growing need for shorter cranks mm , and not just for Ironman athletes.

These are the kind of riders that are going to benefit most from a change in crank length. The biomechanics of cycling is complex and multi-faceted, so concentrating on a single aspect, like crank length, is bound to suffer from oversimplification and generalisation.

Nevertheless, academic researchers have managed to examine this issue with growing sophistication over the last few decades to better understand the influence of crank length on the performance of cyclists. On balance, the weight of the available research indicates that crank length does not influence the speed, power or efficiency of a road cyclist.

What is more important is how the cranks are used, and this is where the training, experience and intrinsic capabilities of the rider make all the difference.

For those riders that have been tempted to try a different crank length based on the promise of extra leverage and perhaps increased efficiency, there are no such gains to be made. The cost of a new crankset will be better spent on formal training with a coach. By contrast, those cyclists that have been suffering with a recurring overuse injury may find relief with a change in crank length, but this is not something that should be attempted through self-directed experimentation.

In addition, it is not always possible to access original research without a subscription. The cranks as a lever Any debate on the influence of crank length normally starts out by considering the problem in terms of simple physics.